Dual filter



FIG. 1 is a front perspective view of the dual filter;

FIG. 2 is a front view of the dual filter;

FIG. 3 is a rear view of the dual filter;

FIG. 4 is a side view of the dual filter;

FIG. 5 is a top view of the dual filter; and,

FIG. 6 is a bottom view of the dual filter.

The broken lines shown in the drawings are for illustrative purposesonly and form no part of the claimed design. The right side view and theleft side view of the dual filter are identical and FIG. 4 is a view ofeither the left or right side of the dual filter.

CLAIM The ornamental design for a dual filter, as shown and described.